Quick change variator

ABSTRACT

A QUICK CHANGE VARIATOR HAS A RING OF SPINDLES CARRYING GEARS SURROUNDING AND SELECTIVELY CONNECTABLE TO EACH STAGE OF A MULTISTAGE SUMMING ASSEMBLY COMPRISING A FIRST STAGE OF STEP DOWN GEARING AND SUBSEQUENT SUMMING DIFFERENTIAL STAGES EACH HAVING THE SAME STEP DOWN RATIO, THE SELECTIVE CONNECTIONS FROM THE SPINDLES BEING MADE BY TRAMSFER GEARS ECCENTRICALLY CARRIED BY SELECTOR PLATES ASSOCIATED WITH EACH STAGE AND MUTUALLY CONNECTED BY MECHANICAL COUNTER TYPE STEPPI NG MECHANISMS AGAIN HAVING THE SAME STEP DOWN RATIO THEREBETWEEN. THE SPINDLES ARE EQUIANGULARLY SPACED WITH RESPECT TO EACH OTHER AND TO MEANS OPERATIVE TO LOCK THE TRANSFER GEARS AGAINST ROTATION, AND ARE ONE LESS IN NUMBER THAN THE STEP DOWN RATIO USED BETWEEN THE SUMMING ASSEMBLY STAGES, THIS LATTER BEING 4,5 OR 6 AND THE NUMBER OF STAGES BEING 3,4,5 OR 6. THE DRIVE TO THE SPINDLES IS SUCH THAT THEY WILL DRIVE THE TRANSFER GEARS ACCORDING TO THE ANGULAR POSITION OF THE LATTER, AT SPEEDS IN SUCCESSIVE INTEGRAL RATIOS INCREASING FROM UNITY. MEANS MAY BE PROVIDED TO PREVENT JAMMING BETWEEN THE GEARS ON THE SPINDLES AND THE TRANSFER GEARS DURING MOVEMENT OF THE SELECTOR PLATES. D R A W I N G

I "Feb.-

. v Q f LaDl L GER H 3,5

QUICK CHANGE VARIATOR Filed Jun 25. 1969 4 Sheets-Sheet 1 INVENTOR LAWRENCE DI LGER ATTOR N E YS I Feb. 2, 1971 L. DI LGER Quicx pgAmE VARIATOR 4 Sheets-Sheet I Filed June 25, 1969.

" Filed June -25, -1969 v QUICK CHANGE. VARIATOR 4 Sheets-Sheet 5 United. States Patent U.S. Cl. 74-681 23 Claims ABSTRACT OF THE DISCLOSURE A quick change variator has a ring of spindles carrying gears surrounding and selectively connectable to each stage of a multistage summing assembly comprising a first stage of step down gearing and subsequent summing differential stages each having the same step down ratio, the selective connections from the spindles being made by transfer gears eccentrically carried by selector plates associated with each stage and mutually connected by mechanical counter type stepping mechanisms again having the same step down ratio therebetween. The spindles are equiangularly spaced with respect to each other and to means operative to lock the transfer gears against rotation, and are one less in number than the step down ratio used between the summing assembly stages, this latter being 4, 5 or 6 and the number of stages being 3, fl, 5 or 6. The drive to the spindles is such that they will drive the transfer gears according to the angular position of the latter, at speeds in successive integral ratios increas ng from unity. Means may be provided to prevent amming between the gears on the spindles and the transfer gears during movement of the selector plates.

This invention is concerned with an improved speedchange mechanism, usually known as a variator, intended for use with counters or registers for computing cost as well as quantity. Although not necessarily limited thereto, a principal use of the variator of the invention is in connection with liquid dispensing apparatus, particularly petrol and other liquid fuel dispensing apparatus.

In known petrol dispensing apparatus, the variator is driven by a meter and produces an output which is proportional to the quantity of petrol dispensedmultiplied by the unit price of the petrol. The mechan sm 18 arranged so that it can be set for any unit price within the range of the variator, but petrol dispensing apparatus which dispenses only one grade of petrol will be operated for long periods of time at the same unit price so that provision for quick change of the variator setting is unnecessary.

However, it is also known in petrol dispensing apparatus to have one dispensing apparatus for delivering a number of grades and blends of petrol of different prices per unit, and in such apparatus, variations n the price and quantity of the fuel to be delivered will probably occur each time a delivery is made because very seldom will two consecutive dispensing operations be concerned with the same grade or blend of petrol or the same quant in such a case of multiple grade petrol dispensing apparatus, a single register for registering price and quantity is desirable, and this requires that the variator therefor will be able to provide for the rapid adjustment of the drive to the cost side of the register each time the grade or blend of petrol is changed. In such variators, therefore, it is necessary to provide for rapidly changing from one speed to another so as to cater for price changes quickly, effectively and accurately.

It will be appreciated that the number of speeds required in such a variator in order to provide a sufficient Patented Feb. 2, 1971 ice range of price settings will be vary large; in practice 999 speed increments upwards from zero are generally required, and it will thus be appreciated that the mechanism of such a variator will tend to be of considerable complexity. At the same time, where the input drive to the variator is derived from a meter, it is important that the loading on the meter be kept to a minimum, which makes it desirable to minimize frictional losses in the variator.

In a known form of variator the input drive is applied via an input shaft geared to a ring of (basically) 9 parallel spindles surrounding a central summing assembly consisting of first, second and third gears arranged to be put in driving connection with further gears on any one of the nine spindles 9r with means preventing rotation of said first, second or third summing input gears, the overall gearing between said input shaft and said first, second or third gear being such that, according to which spindle drive is transferred by, the overall gear ratios will be in the ratio 1:2:3:4:5:6:7:8:9, said first gear and said second gear supplying inputs to a first summing differential, in the case of said first gear via 10:1 reduction gearing; and said first summing differential and said third gear providing input to a second summing differential, in the case of said first summing differential via 10:1 reduction gearing, the output of said second summing differential being the output of the variator, means being provided to select independently with which of said spindles or said locking means each of said first, second and third gears are placed in driving connection.

Such an arrangement will allow selection of any of nine hundred and ninety nine output speeds (representing a corresponding number of price increments) or zero output speed for a given input speed, by using the three selector means to set the units, tens and hundreds of the number of output speed increments above zero that are required. In addition, additional spindles may be provided for selective driving connection with said first gear if the driving connection with this gear is settable to provide speed increments which represent decimal fractions of a price unit and it is desired to provide for non decimal fractions. Similarly, the number of spindles selectively providing driving connection to the third gear could be reduced if a lesser total number of increments were required: thus provision need only be made for connection to the appropriate four spindles if only 499 increments are required. If the number of increments required is greater than 999, then one or more additional summing input gears and summing differential may be provided. It will be understood however that, utilizing the radix 10 as described, a minimum of nine spindles will be required to give a continuous range of increments.

These nine spindles must be driven continuously by the input shaft: additionally, fairly complex gearing must be provided between the input shaft and the gears. The large number of spindles and the associated gearing impose a substantial frictional load on the input shaft, whilst the number of different parts required is large. A variator having, for at least the same number of output speeds, a lesser number of moving parts, and greater standardisation of parts, would be both economically and functionally preferable.

It is an object of the present invention to provide a quick change variator having a reduced number of parts and types of parts and which will impose a reduced load on the input drive for a given overall gear ratio.

We have found that substantial advantages can be achieved by departing from a decimal relationship between the summing stages provided by the summing differentials in the central summing assembly. To provide 999 price increments from zero, the variator must provide (including zero) 10 gear ratios requiring three stages of selective coupling from the spindles to the central summing assembly. However, 9 8 7 and 6 are all greater than 10 and thus by providing (say) only five spindles plus locking means in conjunction with four stages of selective coupling, and reducing the ratio of the reduction gearing between the stages from 10:1 to 6: l, a number of price increments greater than 1000 can be catered for. Provision of only spindles greatly simplifies the problems of driving the spindles and/or connecting them to the summing input gears, whilst reducing the frictional load on the input drive and the number of types of parts required: admittedly, for an equivalent number of price increments one additional summing differential and selective connection means from the spindles will be required, but the latter are in any case simplified and the additional parts required can and normally will be duplicates of parts already employed in the variator.

It should be noted that, assuming that at least 999 price increments are required, these could be provided by three spindles with five stages of selective coupling and four summing differentials; or two spindles with seven coupling stages and six summing differentials, or one spindle with ten coupling stages and nine summing differentials. However, for optimum results in terms of reduction of frietional load, overall reduction in the number of parts employed, compactness and strength, the number of spindles should be selected relative the number of stages of coupling employed so that the reduction ratio between the summing differentials (i.e. the number of spindles plus one) is between 4 and 6 inclusive, and the number of stages (i.e. the number of summing differentials plus one) is between 3 and 6 inclusive. If the number of spindles (and hence said reduction ratio) is reduced too much, it will be apparent from the exemplary figures given above that there is a dispropotrionately large increase in the number of stages required in the variator whilst if the number of spindles is reduced too little, there is a disproportionately small saving in the number of stages required: for example, if a minimum of 999 increments is required, the same number of stages will be required whether 5, 6, 7 or 8 spindles are employed.

Thus where a minimum of 999 increments is required. the use of 5 spindles and four stages, or 3 spindles and 5 stages is preferred, whilst for a minimum of 9999 increments, the use of 4 spindles and 6 stages is preferred: for other minimum numbers of increments, other combinations may be used within the limits laid down above.

Accordingly, the invention provides a variator comprising an input shaft, gearing connecting said input shaft to a ring of xl parallel spindles surrounding a central summing assembly comprising y coaxially arranged summing input gears, each of said spindles carrying y identical drive gears, the drive gears on the several spindles being arranged in rings tangentially to the paths of travel of y transfer gear means engaging respectively the several input gears and mounted respectively on y selector plates rotatable relative to said spindles whereby to provide selective driving connection between, on the one hand, said input gears and, on the other hand, the drive gears or a locking means also arranged tangentially to the scanning paths of each said transfer gear means and adapted when in engagement therewith to prevent rotation of said transfer gear means, a set of said drive gears, one on each Spindle, and said locking means being equiangularly spaced around each selector plate, and the connecting gearing and drive gears being selected so that according to the driving connection to an input gear established by positioning of a selector plate so that the transfer gear means engages the locking means or a drive gear, the overall gear ratios from the input shaft to the corresponding input gear will be in the ratios 0:1:2: x-2:x l, in sequence as the plate is rotated, said summing assembly further comprising y-l summing differentials connected in series, one input of each successive summing differential being connected respectively to the 2nd to yth summing input gears, the

other input of the first summing differential of the series being connected to the first summing input gear via xzl reduction gearing, and at least all but the final summing differentials incorporating x:l input to output reduction gearing, characterized in that x is 4, 5 or 6, that y is between 3 and 6 inclusive, that x is greater than the number of output speed increments required, and that the selector plates are connected by stepping mechanisms adapted to move a plate l/xth of a revolution for each completed revolution of the preceding plate, and in that reversible means are provided to rotate the first selector plate in order to set the variator.

Preferably the xzl reduction gearing associated with the first summing input gear is provided by a further summing differential with one input locked: and preferably also all the summing differentials are identical. Preferred values of x and y are 6 and 4; 0r 4 and 5; or 5 and 6.

In one embodiment of the invention, means are provided adapted to cause axial displacement of the spindles during rotation of the selector plates whereby to disengage the drive gears from the transfer gear means during such rotation. This has the dual object of preventing transmission of torque to the output of the final summing differential, and preventing jamming of the transfer gear means with the drive gears during engagement therebetween.

In an alternative embodiment, the transfer gear means comprise a gear train journalled on each selector plate, one end gear in the train engaging the summing input gear, and the other end gear being adapted to engage the drive gears, said other end gear being journalled in a slot in the selector plate for movement about the axis of the adjacent gear in the chain, said end gear being biased by a spring carried by said plate into a position in which it will selectively engage the drive gears according to the position of the selector plate.

Exemplary embodiments of the invention are described below with reference to the accompanying drawings in which:

FIG. 1 is a side elevation of the input and output end portions of a variator, the central summing assembly and certain parts on the remote side of the variator being omitted for the sake of clarity;

FIG. 2 is a section on the line IIII in FIG. 1;

FIG. 3 is a section on the line III-III in FIG. 1;

FIG. 4 is a plan view of the output end of the variator of FIG. 1;

FIG. 5 is a section on VV in FIG. 4, and

FIG. 6 is a section corresponding to FIG. 3 but showin g a modified form of variator.

It should be noted that certain reference numerals in the drawings are provided with suffixes a, b, c or d where identical parts occur several times in similar juxtapositions. These suflixes will only be referred to in the following description when it is necessary to identify a particular one of said identical parts. Similarly, in certain cases, sufiixes are used in the description to indicate a part which although not shown in the drawings is identical both in construction and juxtaposition to a part which is so shown.

Referring to FIGS. l-5, a variator comprises a supporting framework including a disc shaped end plate 2 and an annular end plate 4, an input gearing support plate 6, and four annular supports for selector p ates 18 each formed by two annular plates 20, 22 having internal flanges 24 trapping external flanges 26 on the selector plates, which are free to rotate relative to the plates 20, 22. The various plates are separated by spacers 28 and the whole secured into a rigid assembly by bolts passing through the spacers 28.

Journalled in apertures through all the plates save plat 4 are a ring of five parallel spindles 32, 34, 36, 38, 40 and a shaft 44. Journalled through apertures in all the plates is a shaft 42, and through plates 2 and 6 only an input shaft 46. The input shaft 46 carries gears 48 and 50, engaging respectively gears 52 and 54 journalled between plates 2 and 6. The gear 52 engages gears 56, 58, 60 secured to spindles 32, 34, 36 respectively whilst the gear 54 engages gears 62, 64 secured to spindles 38, 40 respectively. The numbers of teeth on gears 48, 50, 56, 58, 60, 62, '64 are selected so that on rotation of the shaft 46, the spindles 32-40 will rotate at speeds in the ratio 1:223:4z5. The spindles 3240 each carry four gears 66, one on the far (output) side from the input shaft of each plate 22. All the gears 66 are identical.

'The shaft 42 carries a series of four earns 68, one on the output side of each plate 22, these cams being arranged to act on the one arm of four two-armed levers 70 each pivoted at its fulcrum to the plates 22 and biased by springs 72 towards a position in which a tooth 90 for-med at the outer end of the other of the two arms will engage a transfer gear 74 eccentrically journalled on the corresponding selector plate 18 when the latter is rotated to a suitable position. The gear 74 will also selectively engage the gears 66 adjacent that plate 22 concerned when the plate 18 is in suitable positions, the six positions involved being equidistantly spaced. Thus as the plate is placed in each of these positions successively, it will be locked against rotation by the tooth on the lever 70, or will be rotated at speeds in the ratio 1:223:4z5 by the several gears 66. The annular end plate 4 supports for rotation a cam plate 76 having five circumferentially extending slots 78 through which project the ends of the spindles 32, 34, 36, 38, 40. The slots 78 are flanked by ramps 80 on which bear collars 82 axially secured on the ends of the spindles by circlips. The cam plate 76 is also formed with a radially extending slot 84 engaged by a crank pin 86 carried by an arm 88 secured to the top end of the shaft 42, whereby rotation of the shaft causes rotation of the plate 76, the extent of this rotation and of the rotation of the shaft being limited by the dimensions of the slot. Rotation of the shaft 46 in one direction thus causes the ramps 80 to ride beneath the collars 82 and lift the spindles against the pressure of springs 116 acting between one of the gears 66 on each spindle and washers 118, thus drawing the gears 66 out of the plane of the gears 74, whilst opposite rotation of the shaft 46 allows the collars to ride down the ramps and the gears 66 to return to their original position under the influence of the springs 116. The arms 88 are so set on the shaft in relation to the levers 70 that movement of the gears 66 out of and into the plane of the transfer gears 74 is synchronized with movement of the teeth 90 out of and into a position in which it can engage a gear 74.

The selector plates 18 are provided around the edge of their periphery on their input (related to the position of the input shaft) sides with a ring of teeth 92, and around one-sixth of the edge of their periphery on their output (related to the position .of an output shaft 100) sides with a series of teeth 94 at the same pitch but extending around only one-sixth of their periphery. Journalled on the shaft 44 between each facing pair of plates 20, 22 are three indexing gears 96 provided at each end with teeth 98, 102 engaging or adapted to engage the teeth 92 and 94 respectively, the number of teeth 98, 102 being the same as the number of teeth 94 on each selector plate so that one revolution of a gear 96 corresponds to one-sixth of a revolution of a selector plate whose teeth 92 are in mesh therewith. A gear 104 is secured to the shaft 44 so as to mesh with the teeth 94 of the selector plate 1811.

Thus each rotation of the shaft 44 causes one sixth of a revolution of the plate 18a, whilst once during each complete revolution of plate 18a, its teeth 94 will cause one revolution of the indexing gear 96a which in turn will cause the plate 18b to rotate through one sixth of a revolution, and so on. The shaft 44 is provided at the input end of the variator with a drive connector 106 provided with a click stop device 108 operating once on each rotation of the shaft. Thus, using conventional mechanical counter techniques, the four selector plates may be indexed by successive rotations of the shaft 44 into 6 different combinations of positions in each of which the transfer gear 74 carried by each plate will be in engagement either with a tooth or a gear 66, and the gear 74 on each plate will be either held against rotation or rotated at a rate having a particular relationship to the rate of rotation of the input shaft 46.

The connector 106 is provided with a notch 110 placed so that it can be entered, when the click stop 108 is operative, by a quadrant plate 112 integral with a further drive connector 114 secured to the input end of shaft 42, the entry of this quadrant plate into the notch preventing rotation of the shaft 44, whilst the quadrant plate is so positioned in relation to the shaft 42 that the latter can only be rotated from its position in which the collars 82 are at the tops of the ramps 86 if the quadrant is free to enter the notch 110. Thus the shafts 42 and 44 are interlocked so that the shaft 44 can only be rotated when the teeth 90 and gears 66 are moved clear of the transfer gears 74, and the shaft 42 cannot be moved to allow the teeth 90 and gears 66 to return to their normal positions if the selector plates are between indexing positions as indicated by the click stop. The movement of the gears 66 and the teeth 90 is necessary to prevent the danger of jamming which could occur otherwise as a result of tangential relative movement of the gear teeth during indexing.

The transfer gears 74 are each in engagement with a summing input gear secured to one end of the cage 122 of an epicyclic gear assembly shown generally at 140 to the output side of each plate 22, the axis of the cages also being the axis of the selector plates 18. Each epicyclic gear assembly comprises an axial input gear 124 engaging two planet gears 126 journalled on the support 122 and each coaxially integral with a gear 128, the gears 128 engaging an output gear 130. The number of teeth on the various gears is selected so that the overall stepdown gear ratio from gear 120 to gear 130 with gear 124 stationary, or from gear 124 to gear 130 with gear 120 stationary is 6: 1.

Gear 124a is secured against rotation by means of a pin 132 in a shaft 134a attached to said gear and provided with a sleeve 136a, on which sleeve gear 120a is journalled. Gear 1241) is secured by shaft 13% and a sleeve 136b to gear 130a. Gear 124a is secured by shaft 134a and a sleeve 1360 to gear 13%. Gear 124d is secured by shaft 134d and a sleeve 136d to gear 1300. Gear 130d is secured to the output shaft 100. Thus the epicyclic gear assembly 140a aots purely as a step down gearbox having a 6:1 ratio between the gear 120a and the gear 124b, whilst the remaining epicyclic gear assemblies 140b, 140e, 140a act as summing differentials incorporating 6:1 step down gearing in respect of their outputs at the gears 130b, 130e, 130d.

The gears 120 are each journalled on the corresponding sleeve 136, which latter also serve as journals for the cages 122 and are rotatably supported by the selector plates 18.

In operation, the input shaft 46 is connected to a liquid fuel meter (not shown) providing one rotation of the shaft for a given quantity of fuel metered, the output shaft 100 is connected to a price indicator mechanism (not shown), the connector 106 is connected to a reversible motor (not shown) operative when the price of fuel is to be altered to drive the shaft 42 a number of revolutions in one direction or the other equal to the number of increments by which the price is to be increased or reduced, and the connector 114 is connected to an actuator (not shown) operative to rotate the connector so that the quadrant 112 is turned clear of the notch 110 for the duration of the price presetting operation.

Assuming that all four selector plates are positioned so that the transfer gears 74 engage the teeth 90, and that the connectors 106 and 114 are interlocked, then when the input shaft 46 is rotated by the meter, the gears 66 will all revolve, but there will be no connection to the central summing assembly formed by the epicyclic gear assemblies 140, and since the shaft 134a and the gears 74 are locked against rotation and the assemblies 140 are connected in series, the output shaft is not driven and cannot rotate. There is therefore no driving connection between the input and output shafts.

If the shaft 142 is now operated via the connector 106 so as to disengage the teeth 90 and release the connector 114, and the shaft 44 is driven through this connector through one revolution so as to rotate the selector plate 18a through one-sixth of a revolution, the gear 74a will now be adjacent that gear 6611 on the spindle 32, and when the shaft 142 is returned to its normal position, rotation of the input shaft will cause the gear 74a to be driven via the spindle 32. The assembly 1401: will act as a 6:1 reduction gear, as will the remaining assemblies 140 since their summing inputs through the remaining gears 74 are locked by the teeth 90. The summing assembly as a whole thus acts as a l296z1 (6 :1) reduction gear, and if the gear ratio between the input shaft and the gear 1200 via spindle 32 is 1:11, then the overall ratio of the variator, input to output, will be 1296:11.

1f the shaft 144 is now rotated a further revolution in the same direction (operation of the shaft 42 as described above will henceforth be assumed), drive to the gear 74a will be via the spindle 34, and hence the overall ratio will be 1296:211.

After another revolution of shaft 44 it will be 1296:311. and so on, since the drive ratios to the gears 66 via the spindles 32-40 are in the ratio l:2:3:4:5 as hereinabove described. When the selector plate 181: is being turned by the sixth revolution of shaft 44, its teeth 94 engage the indexing gear 96a and thus drive the selector plate 18]) through one sixth of a revolution. The transfer gear 74a is again locked by the tooth 90a, but the transfer gear 74b is now in engagement with a gear 66 on the spindle 32. Since gears a and 124a are now both locked, gear a and hence gear 124]) are also locked and thus assembly 14011 acts as a 6:1 reduction gear as before, the overall ratio of the variator now being therefore 216111 which equals 1296:611.

On a further revolution of shaft 44, transfer gear 741: reengages gear 66 on spindle 32, and the assembly /1 now acts as a summing differential, giving an overall ratio for the variator of l296:(11+611), equal to 1296:711. On the thirty-sixth revolution of shaft 44, the transfer gear 74c becomes operative, driving the assembly 140c (overall ratio now 36:11, equal to 1296:3611), and at the thirtyseventh revolution, this assembly also beginning to act as a summing differential, the overall ratio of the variator now being 1296:(11l3611) i.e. 1296:37x. On the 216th revolution of shaft 44, the transfer 74d becomes operative, the overall ratio now being 6:11 or 1296121611, and after one more revolution acts as a summing differential, thus giving the overall ratio l296:(11+216n) i.e.

After, for example, 817 revolutions of the shaft 44, the overall ratio will become 1296:(11+ (4 61z) +(4+36)+(3 2-l611) i.e. 1296:81711. Preferably 11 is selected so that equals a small integer, for example 1, 2 or 4.

A modified form of the invention is described with reference to FIG. 6. The shaft 42 and its associated parts in the embodiment already described have the dual function of disconnecting the input drive via the spindle 32:40 during setting of the variator by means of the shaft 44, and preventing jamming of the gears 66 (or teeth 90) and the gears 74 as they enmesh. Where disconnection of the drive during setting is not important, or is achieved by an external clutch, a simpler arrangement may be employed. The shaft 42 and all parts connected to it are eliminated, as are the cam plate 76, the collars 82, and the levers 70, the last being replaced as shown in FIG. 6 by teeth 190 secured directly to the plates 22. The spindles 3240 are located against longitudinal movement.

The transfer gears 74 are each replaced by a train of gears 170, 172 and 174, the gear 174 being in permanent mesh with the gears 120. The gear is carried by a journal 176 slidably mounted in a slot 178 in the selector plate 18, the slot extending in an are centered on the axis of the gear 172. The journal 176 is urged towards the outer end of the slot 178 by a spring 180 mounted in the (fixed) journal 182 of the gear 172, and the gear 174 is thus held resiliently in a position in which it can engage the gears 66. Any tendency to jamming will be overcome by the journal 176 moving against the resilience of the spring and thus allowing the gears 172 and 66 to fall into mesh.

In the embodiments described there are five spindles carrying gears 66, four epicyclic gear assemblies 140 of which three act as summing differentials, and the input to output reduction ratio of each assembly with the other input locked is 6:1. This arrangement provides for 1295 i.e. (6 1) speed increments at the output shaft 100 for a given speed at the input shaft 46. In practice, only 999 speed increments will normally be required or used, and an alternative arrangement may be adopted in which the number of spindles carrying gears 66 is reduced to three, the number of gears 66 on each spindle and of epicyclic gear assemblies 100 is increased to 5 (of which 4 act as summing differentials), and the input to output reduction ratio of each assembly 140 is reduced to 4:1. This arrangement gives 1023 i.e. (4 1) speed increments at the output shaft, the variator operating on exactly the same principles as already described.

If a minimum of 9999 speed increments were required, then the number of spindles used could be four, and of epicyclic gear assemblies 140 six (of which 5 act as summing differentials) and the input to output reduction ratio of each assembly 140 would be 5:1. This arrangement gives 15624 i.e. (5 -1) speed increments at the output shaft. It may be preferred however for reasons of standardisation to use 5 spindles and a 6:1 reduction ratio, giving an actual maximum of 46655 speed increments.

If some other number of speed increments were required, then the number of spindles and assemblies 140 could be adjusted accordingly, for example for 200 increments five spindles and three epicyclic gear assemblies would be suitable, for 500 increments 4 spindles and four epicyclic gear assemblies, and for 500 increments five spindles and five epicyclic gear assemblies. Optimum results are obtained when the number of spindles plus 1 (i.e. the division ration between the stages) is between 4 and 6, and double the number of assemblies 140 acting as summing differentials between 3 and 6 inclusive. Outside these limits the advantages of the invention tend to be lost owing to the excessive increases required for a given number of output speed increments either in the number of spindles, leading to an increased number and diversity of parts and increased input friction, or the number of summing differentials, leading to an increased number of parts and increased length of the variator.

It will have been noted in the embodiment described that all the assemblies 140 are identical. Since assembly 140a does not act as a summing differential, an alternative form of reduction gearing could be utilized: similarly assembly 140d does not strictly require to incorporate any 6:1 reduction function. In the interests of standardisation of parts however, the arrangement described, in which identical assemblies are used, is preferred.

It should also be appreciated that the drive to the spindles may be modified so that the gears 66, although identical on each spindle, vary in their number of teeth for each spindle, the axes of the spindles being adjusted accordingly so as to provide proper meshing with the gears 74. The ratio between the gear ratios provided by the various spindles must however remain 122:3: etc. according to the'number of spindles employed.

What is claimed is:

1. In a variator having a rotary input, a plurality of drive gear sets of ascending order each having a plurality of drive gears of ascending order, drive means connecting the drive gears for simultaneous rotation by the rotary input; a take-oil assembly for each of the drive gear sets comprising take-01f gear means and drive selector means for selectively operating the take-off gear means for being driven by each of the drive gears of the respective drive gear set; a rotary output, summing gear means connecting the take-01f gear means of the take-off assemblies to the rotary output for driving the output in accordance with the drives of the take-off gear means by the selected drive gears, and variator setting means for operating the selector means for setting the overall drive ratio of the variator by setting the drive ratios from the input to the output through each of the drive gear sets and respective take-oil gear means, the improvement wherein there are y drive gear sets and respective take-01f assemblies where y is between 3 and 6 inclusive, wherein there are x-l drive gears in at least all the drive gear sets but the highest order drive gear set where x is between 4 and 6 inclusive; wherein the overall relative drive ratios from the input to the output through the drive gears of ascending order of each drive gear set are in accordance with the arithmetical progression of 1:2:3 respectively; and wherein the overall relative drive ratios from the input to the output through the y take-01f assemblies, for each order of drive gears, are in accordance with the geometrical progression of lzxzx 2. In a variator according to claim 1 wherein x is 6 and y is 4.

3. In a variator according to claim 1 wherein x is 4 and y is 5.

4. In a variator according to claim 1 wherein the drive gears of each drive gear set are angularly spaced in a circular pattern, wherein in each take-off assembly the selector means comprises a selector rotatable within the respective circular pattern and the take-off gear means is mounted on the selector for rotation thereby for selective individual engagement with the drive gears of the respective drive gear set.

5. In a variator according to claim 4 wherein each takeoff gear means comprises a transfer gear mounted on the respective selector for movement between outer and inner radial positions and wherein the take-off assemblies further comprise means biasing the transfer gears outwardly for engagement with the selected drive gears of the drive gear sets respectively.

6. A variator according to claim 4 further comprising locking means for each of the take-off assemblies mounted intermediate two of the angularly spaced drive gears of the respective drive gear set and adapted to be selectively engaged by the respective take-oft gear means by rotation of the respective selector for locking the take off gear means against rotation.

7. A variator according to claim 6 wherein the locking means and the drive gears of at least all but the highest order drive gear set are substantially equiangularly space about 360.

8. A variator according to claim 4 wherein the drive means comprises x-l parallel angularly spaced drive spindles, and wherein the drive gears of each drive gear set are mounted on the drive spindles respectively.

9. A variator according to claim 8 further comprising locking means for each of the take-off assemblies mounted intermediate two of the angularly spaced drive gears of the respective drive gear set and adapted to be selectively engaged by the respective take-oft" gear means "by rotation of the selector and for thereby locking the take-off gear means against rotation, the locking means comprising a locking spindle parallel to the drive spindles and rotatable to selectively activate and deactivate the locking means.

10. In a variator according to claim 8 wherein the variator setting means comprises shifting means for relatively axially shifting the drive gear sets and respective take-off gear means for disengagement thereof.

11. A variator according to claim 10 wherein the shifting means comprises a rotary control plate rotatable for axially shifting the drive spindles and thereby the drive gears mounted thereon to axially shift the drive gear sets from the respective take-off gear means for disengagement thereof.

12. A variator according to claim 11 further comprising locking means for each of the take-01f assemblies having active and inactive positions and wherein the locking means in their active positions are adapted to be engaged by the respective take-off gear means by rotation of the selectors for selectively locking the take-oil gear means against rotation, and wherein the locking means is connected to be actuated to its inactive position when the control plate is rotated to disengage the drive gear sets from the take-off gear means.

13. A variator according to claim 11 wherein the rotary control plate comprises cams engageable with the spindles for axially shifting the spindles upon rotation of the control plate.

14. A variator according to claim 11 wherein the variator setting means comprises a first operator for rotating the selectors for selecting the variator drive ratio, wherein the shifting means comprises a second operator for rotating the control plate to disengage the drive gear sets and respective take-off gear means, and wherein the variator setting means further comprises an interlock between the first and second operators for preventing operation of the first operator to rotate the selectors unless the second operator is operated to rotate the control plate to disengage the drive gear sets and take-ofl? gear means.

15. A variator according to claim 14 wherein the variator setting means comprises a first operator for rotating the selectors for setting the variator drive ratio, a second operator for relatively axially shifting the drive gear sets and respective take-oil gear means for disengagement thereof, and interlock means between the first and second operators for preventing operation of the first operator to rotate the selectors unless the second operator is operated to disengage the drive gear sets and respective take-off gear means.

16. The variator according to claim 8 wherein the overall relative drive ratios from the input to the output through the x1 drive spindles, and through each takeolf gear means, are in accordance with the mathematical progression of 1:223 respectively in sequence around the angularly spaced spindles, and wherein the variator setting means is connected for angularly indexing the rotary selectors in angular steps for sequentially setting the variator drive ratio in equal successive increments in accordance with the mathematical progression of 1:223

17. In a variator comprising a rotary input, a rotary output, an annular arrangement of a plurality of parallel drive spindles connected to the rotary input for being simultaneously driven thereby, a plurality of axially spaced drive gear sets each comprising an annular arrangement of drive gears mounted on the drive spindles respectively for providing different drive ratios from the rotary input, a take-off spindle assembly having an axis parallel to the drive spindles and located centrally within the annular arrangement thereof and comprising a plurality of planetary take-off gears for the drive gear sets respectively and rotatable about the axis of the take-off spindle assembly for selectively engaging each drive gear of the respective 1 1 drive gear set, and summation gear means connecting the take-off gears to the rotary output for driving the output in accordance with the rotation of the take-off gears by the selected drive gears respectively, and variator setting means for setting the overall drive ratio of the variator by angularly setting each take-off gear in engagement with a selected drive gear of the respective drive gear set; the improvement wherein the variator setting means comprises shift means for relatively axially shifting the drive spindles and planetary take-off gears from a first operative relationship in which the take-off gears are axially aligned with the drive gear sets respectively for engagement with the respective drive gears thereof and a second disengaged relationship in which the take-off gears are out of axial alignment with the drive gear sets to permit the take-off gears to be rotated about the axis of the take-off spindle assembly free from engagement with the drive gear sets respectively, and rotary selector means rotatable with the drive spindles and planetary take-off gears in their second disengaged relationship for angularly setting the take-ofi? t gears for engagement with selected drive gears of the drive gear sets respectively.

18. A variator according to claim 17 wherein the shift means provides for relatively axially shifting the drive spindles and take-off spindle assembly for relatively axially shifting the drive spindles and take-off gears between said first operative relationship and second disengaged relationship.

19. A variator according to claim 17 wherein the shift means provide for axially shifting the plurality of parallel drive spindles.

20. A variator according to claim 19 wherein the shift means comprises a collar on each of the parallel drive spindles and a cam plate coaxial with the take-off spindle assembly having a plurality of cams engageable with the spindle collars for axially shifting the spindles in one axial direction by rotation of the cam plate.

21. A variator according to claim 17 wherein the shift means comprises spring means for relatively axially shifting the drive spindles and take-off gears to one of said relationships and positive shifting means operable for positively relatively axially shifting the drive spindles and take-off gears against the bias of the spring means to the other of said relationships.

22. A variator according to claim 17 wherein the shift means comprises rotary control means rotatable between first and second angular positions for relatively axially shifting the drive spindles and take-off gears between said operative and disengaged relationships respectively.

23. A variator according to claim 22 wherein the variator setting means further comprises interlock means for preventing rotation of the rotary selector means unless the rotary control means is in its second angular position providing said disengaged relationship of the drive spindles and take-off gears.

References Cited UNITED STATES PATENTS 2,771,793 11/1956 Robbins 74-681 3,152,724 10/1964 Iauch et al. 74-681 3,238,815 3/1966 Henderhurst et al 74681 CORNELIUS J. HUSAR, Primary Examiner 

